Are there Legionella risks in my workplace?

Any water system, with the right environmental conditions, could be a source for legionella bacteria growth. There is a reasonably foreseeable legionella risk if your water system:

• has a water temperature between 20–45 °C
• creates and/or spreads breathable droplets, e.g. aerosol created by a cooling tower, or water outlets
• stores and/or re-circulates water
• likely to contain a source of food for the organism, e.g. presence of sludge, scale or fouling

The most common sources of legionella in man-made water systems are:

• cooling tower (including evaporative condensers)
• hot and cold water systems
• spa pools

There are also a number of other risk systems that may pose a risk to exposure to legionella, e.g. humidifiers, air washers, emergency showers, indoor ornamental fountains etc.

If you are an employer, or someone in control of premises (e.g. landlord), you have a duty to manage legionella risks. Further information is available in 'What you must do'.

If you decide that the risks are insignificant and are being properly managed to comply with the law, your assessment is complete. You will not need to take any further action, but it is important to review your assessment periodically in case anything changes in your system.